Ref+10 - Reverse thrust always used on the mighty Lockheed stratopig on dirt strips just cancel it before you get enveloped by the dust cloud also helps to see where you going rather than going imc in dust at 50 kts.
KoruLounge/Saudi pc, - the Hamilton Std/Allison combo definitely gives +ve torque, ie engine driving prop, in reverse just airflow reversed. -ve torque could occur in flt but there is a system which prevents that,however don't propose to go into that now unless you're really bored.